As early as 1917, scientific studies had discovered that some sea organisms, including fish, respond to electromagnetic fields and light generated within their aquatic environments. Scientists have shown that catfish in an aquarium exhibit an immediate reaction when an electromagnetic field is applied to water within the aquarium. By the 1950s hundred of fish species were classified and ranked by their degree of response to electromagnetic fields.
It has further been discovered that many fish are capable of sensing electromagnetic impulses generated by other fishes. In fact, some marine research has indicated that some fish, such as sharks, salmon, sturgeon and trout, possess active nerve cells on their bodies that act as electro-receptors that sense electromagnetic fields and can detect changes in the electromagnetic fields, moving ions and charged particles within their aquatic surroundings. Research has shown that some marine life-forms are able to effectively detect and monitor ultraviolet light and/or electro magnetic fields to navigate and locate prey in their aquatic environments.
The research has indicated that a number of marine life species can see or detect objects in water that emit ultraviolet light in the ultraviolet light spectrum of (320 nm-400 nm). This is at least in part because the retinal cones of fish eyes are sensitive to objects that emit ultraviolet light against a dark back drop of deep ocean water. Another reason is that ultraviolet light is effective at attracting marine life is that violet light exhibits a low absorption coefficient in an aquatic environment and, therefore, can be detected by marine life from a distance in aquatic environments.
In a natural aquatic environment, many water organisms such crawfish, grub, minnow, crustacean and even water beetle require to breath and eat all the time in their life cycles. These living activities of water organisms usually create air bubbles and water vibration underwater. In the process of these air bubbles discharging from these organisms, the predators are usually attracted and triggered their eating instinct to hunt their prey by locating where the bubbles are rising from aquatic environment. Some chemical “Bubble Up Power Pellet” fishing products which are water soluble gel capsules or powder with the chemicals of freeze-dried carbon dioxide inside have been widely applied in the sportfishing and commercial fishing markets. However, the chemical residues of these bubble up lure products and their abuse in fishing activities will adversely pollute our aquatic environmental system in the world.
While the chemical capsule is soaking and melting in water, the captured air inside chemicals is freed up as a micro air bubbles in the chemical reaction. In this chemical process of the micro air bubble generation, these oscillating micro air bubbles crackle and pop continuously. Many micro air bubbles deposit together to form the bigger bubbles on the surface of the chemicals and water vibrates as well. When the bubbles start to rise and reach the water surface, they finally burst. They further send out a piercing sound and generate water vibration in the silent underwater environment.
By the studies and theory of bubble physics and aquatic acoustics engineering, we know that the screeching bubble sound which is ultra sound ranging from 50 KHz to 200 KHz is too high-pitched to be heard by human ears. However, the inner ear surrounded by the skull bone of fish with sacculus and otolith sound organ inside are able to hear the underwater high frequency sound. The fishes with lateral line are also able to sense the water vibration. These inner ear and lateral line of fish compose the ocatve-lateralis system which help the fish to survive and hunt in the aquatic environment.
Water is an excellent conducting media of sound wave because it is much denser than air and hence the sound can travel farther in water than in air. As a result, this range of ultra high frequency bubble sound could be emitted and propagated far away from the underwater sound source. The bubble sound wave could be picked up the inner ear of the fish by the “Bone Conduction Principle” in the water while the lateral line of fish could sense the water vibration of bubble generation. Therefore, this ultra bubble sound associated water vibration further attracts and stimulates the predators far away to look for their food around the bubble sound source in aquatic environment. More and more scientific reports on bio-acoustic research have proven that underwater sound and vibrations are the key elements of triggering mechanisms in the biological genetic response of fish to attack their prey. Many lures of top water bubble sound popper have been sold in fishing market. These sound popper lures show that the simulated living bubble sound and water vibrations are not only more effective to attract fishes but also trigger the aggressive eating strike of fish.